Firefox before 1.0.3, Mozilla Suite before 1.7.7, and Netscape 7.2 allows remote attackers to replace existing search plugins with malicious ones using sidebar.addSearchEngine and the same filename as the target engine, which may not be displayed in the GUI, which could then be used to execute malicious script, aka "Firesearching 2."
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A9961
https://exchange.xforce.ibmcloud.com/vulnerabilities/20125
https://bugzilla.mozilla.org/show_bug.cgi?id=290037
http://www.securityfocus.com/bid/15495
http://www.redhat.com/support/errata/RHSA-2005-386.html
http://www.redhat.com/support/errata/RHSA-2005-384.html
http://www.redhat.com/support/errata/RHSA-2005-383.html
http://www.mozilla.org/security/announce/mfsa2005-38.html
http://secunia.com/advisories/14996